PhaFIG 2: Pharynx anatomy.

A. Graphic rendition of the pharynx. The metacorpus is also called the anterior bulb, the median bulb, or the first bulb. The posterior bulb is also called the terminal bulb or the second bulb. At the anterior end, the pharynx is connected to the buccal cavity. At the posterior end, it is connected to the intestine through the pharyngeal-intestinal valve (vpi).
B-F. TEM sections through various parts of the pharyngeal lumen. Section levels are indicated in G.
B. Buccal cavity at the level of the pharyngeal epithelial cells. (Image source: N2T [MRC] A60-24, print 062.)
C. Procorpus. The channels (arrows) are seen at the three corners of the lumen. (Image source: N2W [MRC] A386-2.)
D. Metacorpus at the level of the two ventral gland (Gl) openings and M3 cell bodies. Bacteria (arrows) are seen in channels and the lumen contains a filamentous sieve structure. (Image source: [MRC] JSA-107.)
E. Posterior of the isthmus at the level of the excretory duct. (Image source: N2S [MRC] A1-4.)
F. Grinder in the terminal bulb. (Image source: N2U [MRC] print 401.)
G . DIC micrograph of the pharynx.

Click on picture for full resolution image.